1 | //===- VectorDropLeadUnitDim.cpp - Conversion within the Vector dialect ---===// |
---|---|
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | |
9 | #include <numeric> |
10 | |
11 | #include "mlir/Dialect/Utils/StructuredOpsUtils.h" |
12 | #include "mlir/Dialect/Vector/IR/VectorOps.h" |
13 | #include "mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h" |
14 | #include "mlir/Dialect/Vector/Transforms/VectorTransforms.h" |
15 | #include "mlir/Dialect/Vector/Utils/VectorUtils.h" |
16 | #include "mlir/IR/Builders.h" |
17 | #include "mlir/IR/TypeUtilities.h" |
18 | |
19 | #define DEBUG_TYPE "vector-drop-unit-dim" |
20 | |
21 | using namespace mlir; |
22 | using namespace mlir::vector; |
23 | |
24 | // Trims leading one dimensions from `oldType` and returns the result type. |
25 | // Returns `vector<1xT>` if `oldType` only has one element. |
26 | static VectorType trimLeadingOneDims(VectorType oldType) { |
27 | ArrayRef<int64_t> oldShape = oldType.getShape(); |
28 | ArrayRef<int64_t> newShape = oldShape; |
29 | |
30 | ArrayRef<bool> oldScalableDims = oldType.getScalableDims(); |
31 | ArrayRef<bool> newScalableDims = oldScalableDims; |
32 | |
33 | while (!newShape.empty() && newShape.front() == 1 && |
34 | !newScalableDims.front()) { |
35 | newShape = newShape.drop_front(N: 1); |
36 | newScalableDims = newScalableDims.drop_front(N: 1); |
37 | } |
38 | |
39 | // Make sure we have at least 1 dimension per vector type requirements. |
40 | if (newShape.empty()) { |
41 | newShape = oldShape.take_back(); |
42 | newScalableDims = oldType.getScalableDims().take_back(); |
43 | } |
44 | return VectorType::get(newShape, oldType.getElementType(), newScalableDims); |
45 | } |
46 | |
47 | /// Return a smallVector of size `rank` containing all zeros. |
48 | static SmallVector<int64_t> splatZero(int64_t rank) { |
49 | return SmallVector<int64_t>(rank, 0); |
50 | } |
51 | namespace { |
52 | |
53 | // Casts away leading one dimensions in vector.extract_strided_slice's vector |
54 | // input by inserting vector.broadcast. |
55 | struct CastAwayExtractStridedSliceLeadingOneDim |
56 | : public OpRewritePattern<vector::ExtractStridedSliceOp> { |
57 | using OpRewritePattern::OpRewritePattern; |
58 | |
59 | LogicalResult matchAndRewrite(vector::ExtractStridedSliceOp extractOp, |
60 | PatternRewriter &rewriter) const override { |
61 | // vector.extract_strided_slice requires the input and output vector to have |
62 | // the same rank. Here we drop leading one dimensions from the input vector |
63 | // type to make sure we don't cause mismatch. |
64 | VectorType oldSrcType = extractOp.getSourceVectorType(); |
65 | VectorType newSrcType = trimLeadingOneDims(oldSrcType); |
66 | |
67 | if (newSrcType.getRank() == oldSrcType.getRank()) |
68 | return failure(); |
69 | |
70 | int64_t dropCount = oldSrcType.getRank() - newSrcType.getRank(); |
71 | |
72 | VectorType oldDstType = extractOp.getType(); |
73 | VectorType newDstType = |
74 | VectorType::get(oldDstType.getShape().drop_front(dropCount), |
75 | oldDstType.getElementType(), |
76 | oldDstType.getScalableDims().drop_front(dropCount)); |
77 | |
78 | Location loc = extractOp.getLoc(); |
79 | |
80 | Value newSrcVector = rewriter.create<vector::ExtractOp>( |
81 | loc, extractOp.getVector(), splatZero(dropCount)); |
82 | |
83 | // The offsets/sizes/strides attribute can have a less number of elements |
84 | // than the input vector's rank: it is meant for the leading dimensions. |
85 | auto newOffsets = rewriter.getArrayAttr( |
86 | value: extractOp.getOffsets().getValue().drop_front(dropCount)); |
87 | auto newSizes = rewriter.getArrayAttr( |
88 | value: extractOp.getSizes().getValue().drop_front(dropCount)); |
89 | auto newStrides = rewriter.getArrayAttr( |
90 | value: extractOp.getStrides().getValue().drop_front(dropCount)); |
91 | |
92 | auto newExtractOp = rewriter.create<vector::ExtractStridedSliceOp>( |
93 | loc, newDstType, newSrcVector, newOffsets, newSizes, newStrides); |
94 | |
95 | rewriter.replaceOpWithNewOp<vector::BroadcastOp>(extractOp, oldDstType, |
96 | newExtractOp); |
97 | |
98 | return success(); |
99 | } |
100 | }; |
101 | |
102 | // Casts away leading one dimensions in vector.insert_strided_slice's vector |
103 | // inputs by inserting vector.broadcast. |
104 | struct CastAwayInsertStridedSliceLeadingOneDim |
105 | : public OpRewritePattern<vector::InsertStridedSliceOp> { |
106 | using OpRewritePattern::OpRewritePattern; |
107 | |
108 | LogicalResult matchAndRewrite(vector::InsertStridedSliceOp insertOp, |
109 | PatternRewriter &rewriter) const override { |
110 | VectorType oldSrcType = insertOp.getSourceVectorType(); |
111 | VectorType newSrcType = trimLeadingOneDims(oldSrcType); |
112 | VectorType oldDstType = insertOp.getDestVectorType(); |
113 | VectorType newDstType = trimLeadingOneDims(oldDstType); |
114 | |
115 | int64_t srcDropCount = oldSrcType.getRank() - newSrcType.getRank(); |
116 | int64_t dstDropCount = oldDstType.getRank() - newDstType.getRank(); |
117 | if (srcDropCount == 0 && dstDropCount == 0) |
118 | return failure(); |
119 | |
120 | // Trim leading one dimensions from both operands. |
121 | Location loc = insertOp.getLoc(); |
122 | |
123 | Value newSrcVector = rewriter.create<vector::ExtractOp>( |
124 | loc, insertOp.getValueToStore(), splatZero(srcDropCount)); |
125 | Value newDstVector = rewriter.create<vector::ExtractOp>( |
126 | loc, insertOp.getDest(), splatZero(dstDropCount)); |
127 | |
128 | auto newOffsets = rewriter.getArrayAttr( |
129 | value: insertOp.getOffsets().getValue().take_back(newDstType.getRank())); |
130 | auto newStrides = rewriter.getArrayAttr( |
131 | value: insertOp.getStrides().getValue().take_back(newSrcType.getRank())); |
132 | |
133 | auto newInsertOp = rewriter.create<vector::InsertStridedSliceOp>( |
134 | loc, newDstType, newSrcVector, newDstVector, newOffsets, newStrides); |
135 | |
136 | rewriter.replaceOpWithNewOp<vector::BroadcastOp>(insertOp, oldDstType, |
137 | newInsertOp); |
138 | |
139 | return success(); |
140 | } |
141 | }; |
142 | |
143 | // Casts away leading one dimensions in vector.insert's vector inputs by |
144 | // inserting vector.broadcast. |
145 | struct CastAwayInsertLeadingOneDim : public OpRewritePattern<vector::InsertOp> { |
146 | using OpRewritePattern::OpRewritePattern; |
147 | |
148 | LogicalResult matchAndRewrite(vector::InsertOp insertOp, |
149 | PatternRewriter &rewriter) const override { |
150 | Type oldSrcType = insertOp.getValueToStoreType(); |
151 | Type newSrcType = oldSrcType; |
152 | int64_t oldSrcRank = 0, newSrcRank = 0; |
153 | if (auto type = dyn_cast<VectorType>(oldSrcType)) { |
154 | newSrcType = trimLeadingOneDims(type); |
155 | oldSrcRank = type.getRank(); |
156 | newSrcRank = cast<VectorType>(newSrcType).getRank(); |
157 | } |
158 | |
159 | VectorType oldDstType = insertOp.getDestVectorType(); |
160 | VectorType newDstType = trimLeadingOneDims(oldDstType); |
161 | |
162 | int64_t srcDropCount = oldSrcRank - newSrcRank; |
163 | int64_t dstDropCount = oldDstType.getRank() - newDstType.getRank(); |
164 | if (srcDropCount == 0 && dstDropCount == 0) |
165 | return failure(); |
166 | |
167 | // Trim leading one dimensions from both operands. |
168 | Location loc = insertOp.getLoc(); |
169 | |
170 | Value newSrcVector = insertOp.getValueToStore(); |
171 | if (oldSrcRank != 0) { |
172 | newSrcVector = rewriter.create<vector::ExtractOp>( |
173 | loc, insertOp.getValueToStore(), splatZero(srcDropCount)); |
174 | } |
175 | Value newDstVector = rewriter.create<vector::ExtractOp>( |
176 | loc, insertOp.getDest(), splatZero(dstDropCount)); |
177 | |
178 | // New position rank needs to be computed in two steps: (1) if destination |
179 | // type has leading unit dims, we also trim the position array accordingly, |
180 | // then (2) if source type also has leading unit dims, we need to append |
181 | // zeroes to the position array accordingly. |
182 | unsigned oldPosRank = insertOp.getNumIndices(); |
183 | unsigned newPosRank = std::max<int64_t>(a: 0, b: oldPosRank - dstDropCount); |
184 | SmallVector<OpFoldResult> oldPosition = insertOp.getMixedPosition(); |
185 | SmallVector<OpFoldResult> newPosition = |
186 | llvm::to_vector(Range: ArrayRef(oldPosition).take_back(N: newPosRank)); |
187 | newPosition.resize(newDstType.getRank() - newSrcRank, |
188 | rewriter.getI64IntegerAttr(0)); |
189 | |
190 | auto newInsertOp = rewriter.create<vector::InsertOp>( |
191 | loc, newSrcVector, newDstVector, newPosition); |
192 | |
193 | rewriter.replaceOpWithNewOp<vector::BroadcastOp>(insertOp, oldDstType, |
194 | newInsertOp); |
195 | |
196 | return success(); |
197 | } |
198 | }; |
199 | |
200 | static Value dropUnitDimsFromMask(OpBuilder &b, Location loc, Value mask, |
201 | VectorType newType, AffineMap newMap, |
202 | VectorType oldMaskType) { |
203 | // Infer the type of the new mask from the new map. |
204 | VectorType newMaskType = inferTransferOpMaskType(newType, newMap); |
205 | |
206 | // If the new mask is broadcastable to the old result type, we can safely |
207 | // use a `vector.extract` to get the new mask. Otherwise the best we can |
208 | // do is shape cast. |
209 | if (vector::isBroadcastableTo(srcType: newMaskType, dstVectorType: oldMaskType) == |
210 | BroadcastableToResult::Success) { |
211 | int64_t dropDim = oldMaskType.getRank() - newMaskType.getRank(); |
212 | return b.create<vector::ExtractOp>(loc, mask, splatZero(dropDim)); |
213 | } |
214 | return b.create<vector::ShapeCastOp>(loc, newMaskType, mask); |
215 | } |
216 | |
217 | // Turns vector.transfer_read on vector with leading 1 dimensions into |
218 | // vector.shape_cast followed by vector.transfer_read on vector without leading |
219 | // 1 dimensions. |
220 | struct CastAwayTransferReadLeadingOneDim |
221 | : public OpRewritePattern<vector::TransferReadOp> { |
222 | using OpRewritePattern::OpRewritePattern; |
223 | |
224 | LogicalResult matchAndRewrite(vector::TransferReadOp read, |
225 | PatternRewriter &rewriter) const override { |
226 | // TODO(#78787): Not supported masked op yet. |
227 | if (cast<MaskableOpInterface>(read.getOperation()).isMasked()) |
228 | return failure(); |
229 | // TODO: support 0-d corner case. |
230 | if (read.getTransferRank() == 0) |
231 | return failure(); |
232 | |
233 | auto shapedType = cast<ShapedType>(read.getBase().getType()); |
234 | if (shapedType.getElementType() != read.getVectorType().getElementType()) |
235 | return failure(); |
236 | |
237 | VectorType oldType = read.getVectorType(); |
238 | VectorType newType = trimLeadingOneDims(oldType); |
239 | |
240 | if (newType == oldType) |
241 | return failure(); |
242 | |
243 | AffineMap oldMap = read.getPermutationMap(); |
244 | ArrayRef<AffineExpr> newResults = |
245 | oldMap.getResults().take_back(N: newType.getRank()); |
246 | AffineMap newMap = |
247 | AffineMap::get(dimCount: oldMap.getNumDims(), symbolCount: oldMap.getNumSymbols(), results: newResults, |
248 | context: rewriter.getContext()); |
249 | |
250 | ArrayAttr inBoundsAttr; |
251 | if (read.getInBounds()) |
252 | inBoundsAttr = rewriter.getArrayAttr( |
253 | value: read.getInBoundsAttr().getValue().take_back(newType.getRank())); |
254 | |
255 | Value mask = Value(); |
256 | if (read.getMask()) { |
257 | VectorType maskType = read.getMaskType(); |
258 | mask = dropUnitDimsFromMask(rewriter, read.getLoc(), read.getMask(), |
259 | newType, newMap, maskType); |
260 | } |
261 | |
262 | auto newRead = rewriter.create<vector::TransferReadOp>( |
263 | read.getLoc(), newType, read.getBase(), read.getIndices(), |
264 | AffineMapAttr::get(newMap), read.getPadding(), mask, inBoundsAttr); |
265 | rewriter.replaceOpWithNewOp<vector::BroadcastOp>(read, oldType, newRead); |
266 | |
267 | return success(); |
268 | } |
269 | }; |
270 | |
271 | // Turns vector.transfer_write on vector with leading 1 dimensions into |
272 | // vector.shape_cast followed by vector.transfer_write on vector without leading |
273 | // 1 dimensions. |
274 | struct CastAwayTransferWriteLeadingOneDim |
275 | : public OpRewritePattern<vector::TransferWriteOp> { |
276 | using OpRewritePattern::OpRewritePattern; |
277 | |
278 | LogicalResult matchAndRewrite(vector::TransferWriteOp write, |
279 | PatternRewriter &rewriter) const override { |
280 | // TODO(#78787): Not supported masked op yet. |
281 | if (cast<MaskableOpInterface>(write.getOperation()).isMasked()) |
282 | return failure(); |
283 | // TODO: support 0-d corner case. |
284 | if (write.getTransferRank() == 0) |
285 | return failure(); |
286 | |
287 | auto shapedType = dyn_cast<ShapedType>(write.getBase().getType()); |
288 | if (shapedType.getElementType() != write.getVectorType().getElementType()) |
289 | return failure(); |
290 | |
291 | VectorType oldType = write.getVectorType(); |
292 | VectorType newType = trimLeadingOneDims(oldType); |
293 | if (newType == oldType) |
294 | return failure(); |
295 | int64_t dropDim = oldType.getRank() - newType.getRank(); |
296 | |
297 | AffineMap oldMap = write.getPermutationMap(); |
298 | ArrayRef<AffineExpr> newResults = |
299 | oldMap.getResults().take_back(N: newType.getRank()); |
300 | AffineMap newMap = |
301 | AffineMap::get(dimCount: oldMap.getNumDims(), symbolCount: oldMap.getNumSymbols(), results: newResults, |
302 | context: rewriter.getContext()); |
303 | |
304 | ArrayAttr inBoundsAttr; |
305 | if (write.getInBounds()) |
306 | inBoundsAttr = rewriter.getArrayAttr( |
307 | value: write.getInBoundsAttr().getValue().take_back(newType.getRank())); |
308 | |
309 | auto newVector = rewriter.create<vector::ExtractOp>( |
310 | write.getLoc(), write.getVector(), splatZero(dropDim)); |
311 | |
312 | if (write.getMask()) { |
313 | VectorType maskType = write.getMaskType(); |
314 | Value newMask = dropUnitDimsFromMask( |
315 | rewriter, write.getLoc(), write.getMask(), newType, newMap, maskType); |
316 | rewriter.replaceOpWithNewOp<vector::TransferWriteOp>( |
317 | write, newVector, write.getBase(), write.getIndices(), |
318 | AffineMapAttr::get(newMap), newMask, inBoundsAttr); |
319 | return success(); |
320 | } |
321 | |
322 | rewriter.replaceOpWithNewOp<vector::TransferWriteOp>( |
323 | write, newVector, write.getBase(), write.getIndices(), |
324 | AffineMapAttr::get(newMap), inBoundsAttr); |
325 | return success(); |
326 | } |
327 | }; |
328 | |
329 | } // namespace |
330 | |
331 | FailureOr<Value> |
332 | mlir::vector::castAwayContractionLeadingOneDim(vector::ContractionOp contractOp, |
333 | MaskingOpInterface maskingOp, |
334 | RewriterBase &rewriter) { |
335 | VectorType oldAccType = dyn_cast<VectorType>(contractOp.getAccType()); |
336 | if (oldAccType == nullptr) |
337 | return failure(); |
338 | if (oldAccType.getRank() < 2) |
339 | return failure(); |
340 | if (oldAccType.getShape()[0] != 1) |
341 | return failure(); |
342 | // currently we support only dropping one dim but the pattern can be applied |
343 | // greedily to drop more. |
344 | int64_t dropDim = 1; |
345 | |
346 | auto oldIndexingMaps = contractOp.getIndexingMapsArray(); |
347 | SmallVector<AffineMap> newIndexingMaps; |
348 | |
349 | auto oldIteratorTypes = contractOp.getIteratorTypes(); |
350 | SmallVector<Attribute> newIteratorTypes; |
351 | |
352 | int64_t dimToDrop = oldIndexingMaps[2].getDimPosition(0); |
353 | |
354 | if (!isParallelIterator(oldIteratorTypes[dimToDrop])) |
355 | // only parallel type iterators can be dropped. |
356 | return failure(); |
357 | |
358 | for (const auto &it : llvm::enumerate(oldIteratorTypes)) { |
359 | int64_t currDim = it.index(); |
360 | if (currDim == dimToDrop) |
361 | continue; |
362 | newIteratorTypes.push_back(it.value()); |
363 | } |
364 | |
365 | SmallVector<Value> operands = {contractOp.getLhs(), contractOp.getRhs(), |
366 | contractOp.getAcc()}; |
367 | SmallVector<Value> newOperands; |
368 | auto loc = contractOp.getLoc(); |
369 | |
370 | for (const auto &it : llvm::enumerate(oldIndexingMaps)) { |
371 | // Check if the dim to be dropped exists as a leading dim in the operand |
372 | // if it does then we use vector.extract to drop it. |
373 | bool validExtract = false; |
374 | SmallVector<AffineExpr> results; |
375 | auto map = it.value(); |
376 | int64_t orginalZeroDim = it.value().getDimPosition(0); |
377 | if (orginalZeroDim != dimToDrop) { |
378 | // There are two reasons to be in this path, 1. We need to |
379 | // transpose the operand to make the dim to be dropped |
380 | // leading. 2. The dim to be dropped does not exist and in |
381 | // that case we dont want to add a unit transpose but we must |
382 | // check all the indices to make sure this is the case. |
383 | bool transposeNeeded = false; |
384 | SmallVector<int64_t> perm; |
385 | SmallVector<AffineExpr> transposeResults; |
386 | |
387 | for (int64_t i = 0, e = map.getNumResults(); i < e; ++i) { |
388 | int64_t currDim = map.getDimPosition(i); |
389 | if (currDim == dimToDrop) { |
390 | transposeNeeded = true; |
391 | perm.insert(perm.begin(), i); |
392 | auto targetExpr = rewriter.getAffineDimExpr(currDim); |
393 | transposeResults.insert(transposeResults.begin(), targetExpr); |
394 | } else { |
395 | perm.push_back(i); |
396 | auto targetExpr = rewriter.getAffineDimExpr(currDim); |
397 | transposeResults.push_back(targetExpr); |
398 | } |
399 | } |
400 | |
401 | // Checks if only the outer, unit dimensions (of size 1) are permuted. |
402 | // Such transposes do not materially effect the underlying vector and can |
403 | // be omitted. EG: perm [1, 0, 2] applied to vector<1x1x8xi32> |
404 | bool transposeNonOuterUnitDims = false; |
405 | auto operandShape = cast<ShapedType>(operands[it.index()].getType()); |
406 | for (auto [index, dim] : |
407 | llvm::enumerate(ArrayRef<int64_t>(perm).drop_back(1))) { |
408 | if (dim != static_cast<int64_t>(index) && |
409 | operandShape.getDimSize(index) != 1) { |
410 | transposeNonOuterUnitDims = true; |
411 | break; |
412 | } |
413 | } |
414 | |
415 | // Do the transpose now if needed so that we can drop the |
416 | // correct dim using extract later. |
417 | if (transposeNeeded) { |
418 | map = AffineMap::get(map.getNumDims(), 0, transposeResults, |
419 | contractOp.getContext()); |
420 | if (transposeNonOuterUnitDims) { |
421 | operands[it.index()] = rewriter.createOrFold<vector::TransposeOp>( |
422 | loc, operands[it.index()], perm); |
423 | } |
424 | } |
425 | } |
426 | // We have taken care to have the dim to be dropped be |
427 | // the leading dim. If its still not leading that means it |
428 | // does not exist in this operand and hence we do not need |
429 | // an extract. |
430 | if (map.getDimPosition(0) == dimToDrop) |
431 | validExtract = true; |
432 | |
433 | for (int64_t i = 0, e = map.getNumResults(); i < e; ++i) { |
434 | int64_t currDim = map.getDimPosition(i); |
435 | if (currDim == dimToDrop) |
436 | // This is the dim we are dropping. |
437 | continue; |
438 | auto targetExpr = rewriter.getAffineDimExpr( |
439 | currDim < dimToDrop ? currDim : currDim - 1); |
440 | results.push_back(targetExpr); |
441 | } |
442 | newIndexingMaps.push_back(AffineMap::get(map.getNumDims() - 1, 0, results, |
443 | contractOp.getContext())); |
444 | // Extract if its a valid extraction, otherwise use the operand |
445 | // without extraction. |
446 | newOperands.push_back( |
447 | validExtract ? rewriter.create<vector::ExtractOp>( |
448 | loc, operands[it.index()], splatZero(dropDim)) |
449 | : operands[it.index()]); |
450 | } |
451 | |
452 | // Depending on whether this vector.contract is masked, the replacing Op |
453 | // should either be a new vector.contract Op or vector.mask Op. |
454 | Operation *newOp = rewriter.create<vector::ContractionOp>( |
455 | loc, newOperands[0], newOperands[1], newOperands[2], |
456 | rewriter.getAffineMapArrayAttr(newIndexingMaps), |
457 | rewriter.getArrayAttr(newIteratorTypes), contractOp.getKind()); |
458 | |
459 | if (maskingOp) { |
460 | auto newMask = rewriter.create<vector::ExtractOp>(loc, maskingOp.getMask(), |
461 | splatZero(dropDim)); |
462 | |
463 | newOp = mlir::vector::maskOperation(builder&: rewriter, maskableOp: newOp, mask: newMask); |
464 | } |
465 | |
466 | return rewriter |
467 | .create<vector::BroadcastOp>(loc, contractOp->getResultTypes()[0], |
468 | newOp->getResults()[0]) |
469 | .getResult(); |
470 | } |
471 | |
472 | namespace { |
473 | |
474 | /// Turns vector.contract on vector with leading 1 dimensions into |
475 | /// vector.extract followed by vector.contract on vector without leading |
476 | /// 1 dimensions. Also performs transpose of lhs and rhs operands if required |
477 | /// prior to extract. |
478 | struct CastAwayContractionLeadingOneDim |
479 | : public MaskableOpRewritePattern<vector::ContractionOp> { |
480 | using MaskableOpRewritePattern::MaskableOpRewritePattern; |
481 | |
482 | FailureOr<Value> |
483 | matchAndRewriteMaskableOp(vector::ContractionOp contractOp, |
484 | MaskingOpInterface maskingOp, |
485 | PatternRewriter &rewriter) const override { |
486 | return castAwayContractionLeadingOneDim(contractOp, maskingOp, rewriter); |
487 | } |
488 | }; |
489 | |
490 | /// Looks at elementwise operations on vectors with at least one leading |
491 | /// dimension equal 1, e.g. vector<1x[4]x1xf32> (but not vector<2x[4]x1xf32>), |
492 | /// and cast aways the leading one dimensions (_plural_) and then broadcasts |
493 | /// the results. |
494 | /// |
495 | /// Example before: |
496 | /// %1 = arith.mulf %arg0, %arg1 : vector<1x4x1xf32> |
497 | /// Example after: |
498 | /// %2 = arith.mulf %0, %1 : vector<4x1xf32> |
499 | /// %3 = vector.broadcast %2 : vector<4x1xf32> to vector<1x4x1xf32> |
500 | /// |
501 | /// Does support scalable vectors. |
502 | class CastAwayElementwiseLeadingOneDim : public RewritePattern { |
503 | public: |
504 | CastAwayElementwiseLeadingOneDim(MLIRContext *context, |
505 | PatternBenefit benefit = 1) |
506 | : RewritePattern(MatchAnyOpTypeTag(), benefit, context) {} |
507 | |
508 | LogicalResult matchAndRewrite(Operation *op, |
509 | PatternRewriter &rewriter) const override { |
510 | if (!OpTrait::hasElementwiseMappableTraits(op) || op->getNumResults() != 1) |
511 | return failure(); |
512 | auto vecType = dyn_cast<VectorType>(op->getResultTypes()[0]); |
513 | if (!vecType) |
514 | return failure(); |
515 | VectorType newVecType = trimLeadingOneDims(vecType); |
516 | if (newVecType == vecType) |
517 | return failure(); |
518 | int64_t dropDim = vecType.getRank() - newVecType.getRank(); |
519 | SmallVector<Value, 4> newOperands; |
520 | for (Value operand : op->getOperands()) { |
521 | if (auto opVecType = dyn_cast<VectorType>(operand.getType())) { |
522 | newOperands.push_back(rewriter.create<vector::ExtractOp>( |
523 | op->getLoc(), operand, splatZero(dropDim))); |
524 | } else { |
525 | newOperands.push_back(Elt: operand); |
526 | } |
527 | } |
528 | Operation *newOp = |
529 | rewriter.create(op->getLoc(), op->getName().getIdentifier(), |
530 | newOperands, newVecType, op->getAttrs()); |
531 | rewriter.replaceOpWithNewOp<vector::BroadcastOp>(op, vecType, |
532 | newOp->getResult(0)); |
533 | return success(); |
534 | } |
535 | }; |
536 | |
537 | // Drops leading 1 dimensions from vector.constant_mask and inserts a |
538 | // vector.broadcast back to the original shape. |
539 | struct CastAwayConstantMaskLeadingOneDim |
540 | : public OpRewritePattern<vector::ConstantMaskOp> { |
541 | using OpRewritePattern::OpRewritePattern; |
542 | |
543 | LogicalResult matchAndRewrite(vector::ConstantMaskOp mask, |
544 | PatternRewriter &rewriter) const override { |
545 | VectorType oldType = mask.getType(); |
546 | VectorType newType = trimLeadingOneDims(oldType); |
547 | |
548 | if (newType == oldType) |
549 | return failure(); |
550 | |
551 | int64_t dropDim = oldType.getRank() - newType.getRank(); |
552 | ArrayRef<int64_t> dimSizes = mask.getMaskDimSizes(); |
553 | |
554 | // If any of the dropped unit dims has a size of `0`, the entire mask is a |
555 | // zero mask, else the unit dim has no effect on the mask. |
556 | int64_t flatLeadingSize = |
557 | std::accumulate(first: dimSizes.begin(), last: dimSizes.begin() + dropDim + 1, |
558 | init: static_cast<int64_t>(1), binary_op: std::multiplies<int64_t>()); |
559 | SmallVector<int64_t> newDimSizes = {flatLeadingSize}; |
560 | newDimSizes.append(in_start: dimSizes.begin() + dropDim + 1, in_end: dimSizes.end()); |
561 | |
562 | auto newMask = rewriter.create<vector::ConstantMaskOp>( |
563 | mask.getLoc(), newType, newDimSizes); |
564 | rewriter.replaceOpWithNewOp<vector::BroadcastOp>(mask, oldType, newMask); |
565 | return success(); |
566 | } |
567 | }; |
568 | |
569 | } // namespace |
570 | |
571 | void mlir::vector::populateCastAwayVectorLeadingOneDimPatterns( |
572 | RewritePatternSet &patterns, PatternBenefit benefit) { |
573 | patterns |
574 | .add<CastAwayExtractStridedSliceLeadingOneDim, |
575 | CastAwayInsertStridedSliceLeadingOneDim, CastAwayInsertLeadingOneDim, |
576 | CastAwayConstantMaskLeadingOneDim, CastAwayTransferReadLeadingOneDim, |
577 | CastAwayTransferWriteLeadingOneDim, CastAwayElementwiseLeadingOneDim, |
578 | CastAwayContractionLeadingOneDim>(arg: patterns.getContext(), args&: benefit); |
579 | } |
580 |
Definitions
- trimLeadingOneDims
- splatZero
- CastAwayExtractStridedSliceLeadingOneDim
- matchAndRewrite
- CastAwayInsertStridedSliceLeadingOneDim
- matchAndRewrite
- CastAwayInsertLeadingOneDim
- matchAndRewrite
- dropUnitDimsFromMask
- CastAwayTransferReadLeadingOneDim
- matchAndRewrite
- CastAwayTransferWriteLeadingOneDim
- matchAndRewrite
- castAwayContractionLeadingOneDim
- CastAwayContractionLeadingOneDim
- matchAndRewriteMaskableOp
- CastAwayElementwiseLeadingOneDim
- CastAwayElementwiseLeadingOneDim
- matchAndRewrite
- CastAwayConstantMaskLeadingOneDim
- matchAndRewrite
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